Converting An Easy Bake Oven To USB

Easy Bake Ovens have changed a lot since you burnt down your house by installing a 100 Watt light bulb inside one. Now, Easy Bake Ovens are [bigclive] material. It’s a piece of nichrome wire connected through a switch across mains power. Part of the nichrome wire is a resistor divider used to power a light. This light assembly is just a LED, some resistors, and a diode wired anti-parallel to the LED.

This is a device designed for 120 V, but [Jason] wanted it to run on USB-C. While there are USB-C chargers that will supply enough power for an Easy Bake Oven, the voltage is limited to 20V. Rather than step up the USB-C voltage, [Jason] added some nichrome wires to divide it into six equal segments, then wired all the segments in parallel. This lowers the voltage by one sixth and increases the current by a factor of six. Good enough.

The power supply used for this hack is the official Apple 87W deal, with a USB-C breakout board (available on Tindie, buy some stuff on Tindie. Superliminial advertising) an Arduino Uno connected to the I2C pins. A few bits of code later, and [Jason] had a lot of power coming over a USB cable.

With the Easy Bake Oven fully converted, [Jason] whipped up a batch of cookie mix. After about 15 minutes the cookies crisped up and started to look almost appetizing.

While the result is weird — who on Earth would ever want a USB-powered Easy Bake Oven — this is honestly a fantastic test of [Jason]’s USB-C PHY breakout board. What better way to test a USB-C than a big resistive load, and what better resistive load is there than an Easy Bake Oven? It’s brilliant and hilarious at the same time.

As a kid, my sister’s ran on a 12V car light bulb, I think maybe from an indicator. Off a great big brick of a transformer. It meant there were no dangerous voltages outside the sealed plastic brick, and it couldn’t generate enough heat to cause any proper burns.

On top of the bulb was a takeaway foil can, on a lever that flipped it into place over the bulb (which is under a grille). So it’s a teeny takeaway-sized area reflecting IR from a bulb into a teeny wee area, for making very small cakes.

I wondered before she got it, how it could possibly work, glad I do. Surprised the American one uses mains. Is it the official Hasbro (or whoever) model you / Jason are talking about here?

I read it as if the nichrome had been cut into six lengths that were then put in parallel. Before they were cut each length would have had 20 Volts across it (120V / 6) and now they have 19 Volts so it seems it is close to the same power and with the same current per segment but 6 times the total current as the segments are now in parallel.

Realistically though the length and resistance of nichrome changes as it expands with temperature. It has a positive temperature co-efficient (PTC). So I would expect the power consumption to be close to exactly the same.

Oh dear, Brian Benchoff strikes again. I’d have assumed you knew your way around fractions, with the foolish fanboying of SAE units &c., but I might have been mistaken. Lowering the voltage BY one sixth is not the same as lowering the voltage TO one sixth. This is just very sloppy writing. I hope you can do better.

In parallel, but the opposite direction. So the LED faces with it’s anode one way. The diode is in parallel with the LED, but it’s anode faces the other way. Anti-parallel. Mostly a word you’ll see used about diodes. Also “inverse parallel”.

Actually the best example is probably a bi-colour LED. 2-pin LED housing containing a red and a green LED chip, connected together in anti-parallel. Depending on the polarity you connect it with, either colour will light. If you rapidly switch it’s polarity, you get yellow. Or orange with the right timing periods.